In the manufacture of plastic closures by compression molding and the provision of liners in plastic closures, it is common to utilize pellet delivery systems. Typical patents showing such systems are: U.S. Pat. Nos. 2,640,033, 3,458,897, 3,676,029, 3,828,637, 3,955,605, 4,080,136, 4,157,048, 4,269,584, 4,277,431, 4,440,704, 4,800,792 and 4,978,288.
In one type of system which has been used as shown in U.S. Pat. Nos. 4,080,136 and 4,277,431, a flexible and resilient blade is moved along a surface surrounding the extrusion nozzle and after it moves past the surface snaps to accelerate the pellet to the place of use. It has been found that such a system is difficult to set up and requires substantial attention. Furthermore, it requires frequent adjustment. In addition, it has limited life and must be replaced rather frequently.
Accordingly among the objectives of the present invention are to provide a pellet delivery system that is less dependent upon operating skill, needs less attention, utilizes a construction that has longer life; provides better alignment of a cutting knife blade with respect to the extrusion orifice, and provides for better control and placement of the pellet.
In accordance with the invention a plastic pellet delivery system including an extruder nozzle having an orifice and an arcuate surface adjacent the orifice and rigid cutting knife which is eccentrically mounted on a shaft that is positioned and is rotated adjacent the orifice to move the rigid knife eccentrically into and out of engagement with the nozzle surface. The cutting knife is mounted for limited yielding pivotal movement relative to the eccentric such that it will deflect angularly with respect to the eccentric mount as it is engaging the nozzle surface such that the free edge of the knife blade tip is moved radially inwardly as the eccentric mount is rotated providing a substantially constant force of the blade against the nozzle surface.